{"id":"CVE-2026-52908","state":"PUBLISHED","title":"RDMA: During rereg_mr ensure that REREG_ACCESS is compatible","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA: During rereg_mr ensure that REREG_ACCESS is compatible\n\nIf IB_MR_REREG_ACCESS changes from RO to RW then the umem has to be\nre-evaluated to ensure it is properly pinned as RW. Since the umem is\nhidden inside each driver's mr struct add a ib_umem_check_rereg() function\nthat each driver has to call before processing IB_MR_REREG_ACCESS.\n\nmlx4 has to retain its duplicate ib_access_writable check because it\nimplements IB_MR_REREG_ACCESS | IB_MR_REREG_TRANS by changing both items\nin place sequentially while the MR is live, so it will continue to not\nsupport this combination.","publishedAt":"2026-06-19T14:00:35.971Z","updatedAt":"2026-10-19T19:36:59.343Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b40656aa7d559adc1fe689396dc58b92a9a27286","status":"affected","lessThan":"09dc18894148381d3bfc550083b1236043870dce","versionType":"git"},{"version":"b40656aa7d559adc1fe689396dc58b92a9a27286","status":"affected","lessThan":"eba5df21eda0fe7418efbea2f799f8ea1b8ca94c","versionType":"git"},{"version":"b40656aa7d559adc1fe689396dc58b92a9a27286","status":"affected","lessThan":"2904e985a2917b5dac65df82733065e78a65fc9d","versionType":"git"},{"version":"b40656aa7d559adc1fe689396dc58b92a9a27286","status":"affected","lessThan":"50334a05a950840b39a1ce3d2a173b4183db9b3e","versionType":"git"},{"version":"b40656aa7d559adc1fe689396dc58b92a9a27286","status":"affected","lessThan":"badad6fad60def1b9805559dd81dbab3d97b82aa","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/core/umem.c","drivers/infiniband/hw/hns/hns_roce_mr.c","drivers/infiniband/hw/irdma/verbs.c","drivers/infiniband/hw/mlx4/mr.c","drivers/infiniband/hw/mlx5/mr.c","drivers/infiniband/sw/rxe/rxe_verbs.c","include/rdma/ib_umem.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.2","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/core/umem.c","drivers/infiniband/hw/hns/hns_roce_mr.c","drivers/infiniband/hw/irdma/verbs.c","drivers/infiniband/hw/mlx4/mr.c","drivers/infiniband/hw/mlx5/mr.c","drivers/infiniband/sw/rxe/rxe_verbs.c","include/rdma/ib_umem.h"]}],"references":["https://git.kernel.org/stable/c/09dc18894148381d3bfc550083b1236043870dce","https://git.kernel.org/stable/c/eba5df21eda0fe7418efbea2f799f8ea1b8ca94c","https://git.kernel.org/stable/c/2904e985a2917b5dac65df82733065e78a65fc9d","https://git.kernel.org/stable/c/50334a05a950840b39a1ce3d2a173b4183db9b3e","https://git.kernel.org/stable/c/badad6fad60def1b9805559dd81dbab3d97b82aa"],"weaknesses":["CWE-285"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/52xxx/CVE-2026-52908.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52908","state":"PUBLISHED","datePublished":"2026-06-19T14:00:35.971Z","dateUpdated":"2026-10-19T19:36:59.343Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.366Z"},"containers":{"cna":{"title":"RDMA: During rereg_mr ensure that REREG_ACCESS is compatible","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA: During rereg_mr ensure that REREG_ACCESS is compatible\n\nIf IB_MR_REREG_ACCESS changes from RO to RW then the umem has to be\nre-evaluated to ensure it is properly pinned as RW. Since the umem is\nhidden inside each driver's mr struct add a ib_umem_check_rereg() function\nthat each driver has to call before processing IB_MR_REREG_ACCESS.\n\nmlx4 has to retain its duplicate ib_access_writable check because it\nimplements IB_MR_REREG_ACCESS | IB_MR_REREG_TRANS by changing both items\nin place sequentially while the MR is live, so it will continue to not\nsupport this combination."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b40656aa7d559adc1fe689396dc58b92a9a27286","status":"affected","lessThan":"09dc18894148381d3bfc550083b1236043870dce","versionType":"git"},{"version":"b40656aa7d559adc1fe689396dc58b92a9a27286","status":"affected","lessThan":"eba5df21eda0fe7418efbea2f799f8ea1b8ca94c","versionType":"git"},{"version":"b40656aa7d559adc1fe689396dc58b92a9a27286","status":"affected","lessThan":"2904e985a2917b5dac65df82733065e78a65fc9d","versionType":"git"},{"version":"b40656aa7d559adc1fe689396dc58b92a9a27286","status":"affected","lessThan":"50334a05a950840b39a1ce3d2a173b4183db9b3e","versionType":"git"},{"version":"b40656aa7d559adc1fe689396dc58b92a9a27286","status":"affected","lessThan":"badad6fad60def1b9805559dd81dbab3d97b82aa","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/core/umem.c","drivers/infiniband/hw/hns/hns_roce_mr.c","drivers/infiniband/hw/irdma/verbs.c","drivers/infiniband/hw/mlx4/mr.c","drivers/infiniband/hw/mlx5/mr.c","drivers/infiniband/sw/rxe/rxe_verbs.c","include/rdma/ib_umem.h"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.2","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/core/umem.c","drivers/infiniband/hw/hns/hns_roce_mr.c","drivers/infiniband/hw/irdma/verbs.c","drivers/infiniband/hw/mlx4/mr.c","drivers/infiniband/hw/mlx5/mr.c","drivers/infiniband/sw/rxe/rxe_verbs.c","include/rdma/ib_umem.h"]}],"references":[{"url":"https://git.kernel.org/stable/c/09dc18894148381d3bfc550083b1236043870dce"},{"url":"https://git.kernel.org/stable/c/eba5df21eda0fe7418efbea2f799f8ea1b8ca94c"},{"url":"https://git.kernel.org/stable/c/2904e985a2917b5dac65df82733065e78a65fc9d"},{"url":"https://git.kernel.org/stable/c/50334a05a950840b39a1ce3d2a173b4183db9b3e"},{"url":"https://git.kernel.org/stable/c/badad6fad60def1b9805559dd81dbab3d97b82aa"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable path is reached through local RDMA uverbs write/ioctl operations on /dev/infiniband/uverbs*, not by unauthenticated network packets. Remote RDMA traffic may perform the final write only after a local process has created and reregistered the MR.\nAC:L - The trigger is a deterministic sequence: register an MR read-only, reregister it with writable access without changing translation, then use the writable MR. There is no race or attacker-uncontrolled timing requirement.\nPR:L - A basic local user can open the uverbs device when an RDMA device is exposed and create the required context, PD, and MR; the path has no CAP_SYS_ADMIN or CAP_NET_ADMIN gate. Resource limits may constrain size but do not make the attack require administrator privileges.\nUI:N - No victim action is required after the attacker has local execution and access to the RDMA uverbs device. The attacker drives the registration, reregistration, and write operations directly.\nS:U - The impact remains within the kernel/host security authority and is a local privilege escalation or host integrity violation. It does not inherently cross a VM, hypervisor, or IOMMU security boundary.\nC:H - The stale read-only pin can be converted into a writable RDMA mapping, enabling modification of read-only/COW or page-cache backed memory in a Dirty-COW-like way. A plausible privileged-code-execution path through corrupted executable page cache yields full confidentiality impact.\nI:H - The bug creates an unauthorized write primitive to pages that were not pinned with FOLL_WRITE and should not be writable. This can corrupt read-only user mappings or shared page-cache contents, making high integrity impact defensible.\nA:H - The same unauthorized write primitive can corrupt executable/library page cache or process memory and crash privileged services or destabilize the system. With plausible root code execution, high availability impact is also defensible."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:31:31.552Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.12.94"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.18.36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"7.0.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-52908","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:22:22.777962Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-285","lang":"en","type":"CWE","description":"CWE-285 Improper Authorization"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:36:59.343Z"}}]}}}